The economist Joseph Schumpeter long ago argued that crises were seedbeds of innovation and entrepreneurship. In today's economic crisis, we certainly need all the innovation we can get, particularly in addressing big social challenges, such as rising youth unemployment and the care needs of an ageing population.

As a social investor that invests in and supports organisations that are using digital technology for social good, it is inspiring to see just how many social enterprises are using technology as a tool for innovation. We're seeing an ever-increasing tide of inspiring individuals who recognise the potential of technology to support new forms of collaboration, untap and reorganise resources across communities and create new opportunities for social participation. It is also interesting to see that the most effective examples of positive social change result from collaboration across the public, private and third sectors.

FutureGov is an example of a social enterprise that is using technology to address a big social challenge. Recognising that there are numerous agencies involved in the complex and challenging world of child protection, FutureGov's Patchwork project used social media to put children and their families at the centre of the professional support networks, bridging the communication gaps between agencies.

Patchwork is an app that enables any member of a family's team to administer their case, breaking down organisational silos in public services and also empowering frontline staff and the family to maintain an up-to-date picture of who's involved.

The Patchwork prototype was co-designed in Lichfield, Staffordshire, with a project team that included children's charity Barnardo's, technologists, policy advisers and family representatives. They developed a concept for how social technology could contribute to keeping children safe. It is the buy-in and collaboration from the senior leadership teams across the various child protection agencies and support services that has been the key to Patchwork's success. As part of the prototype phase, FutureGov developed a change management methodology to ensure the technology influenced wider attitudinal change among public agencies working with children. An investment by Nominet Trust, the social enterprise I run, is helping FutureGov to develop the prototype into a service that can be scaled across all 400 UK local authority areas.

Nominet Trust funding has also been able to help Cockermouth Centre for the Third Age, on the edge of the Lake District, to develop a "virtual centre". Using an online platform, GPs can refer patients who are lonely, mildly depressed or have mobility issues to the volunteer-run centre which offers company, help with shopping, training on the internet and generally a shoulder to lean on.

In the first three months of the Cockermouth project, emergency admissions to hospital were down by 143 on the previous year. Its founders were asked by the Department of Health to write a paper on how this model for GP engagement could be replicated nationally.

A key factor in the success of both projects is the early collaboration between the public, private and third sectors. Herein lies the challenge: we need to find new opportunities for cross-sector collaboration that draw on the imagination, expertise and networks across industry, government and social enterprise to develop co-designed and scalable solutions to big social challenges.

These projects demonstrate how digital technology can help us to redesign how we address social challenges. At a time of financial constraint, we need to be particularly innovative in our use of resources. Technology gives us the opportunity to think differently, develop new social connections and reorganise resources across communities. When approached by nimble, enthusiastic social entrepreneurs who are prepared to test out genuinely new approaches, the role for public managers is to embrace these new forms of collaboration.

• Annika Small is director of the Nominet Trust, which invests in projects where digital resources are being mobilised to create positive social change